/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2014 The FreeBSD Foundation
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/event.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <assert.h>
#include <errno.h>
#include <libutil.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
#define AUTOUNMOUNTD_PIDFILE "/var/run/autounmountd.pid"
struct automounted_fs {
TAILQ_ENTRY(automounted_fs) af_next;
time_t af_mount_time;
bool af_mark;
fsid_t af_fsid;
char af_mountpoint[MNAMELEN];
};
static TAILQ_HEAD(, automounted_fs) automounted;
static struct automounted_fs *
automounted_find(fsid_t fsid)
{
struct automounted_fs *af;
TAILQ_FOREACH(af, &automounted, af_next) {
if (fsidcmp(&af->af_fsid, &fsid) == 0)
return (af);
}
return (NULL);
}
static struct automounted_fs *
automounted_add(fsid_t fsid, const char *mountpoint)
{
struct automounted_fs *af;
af = calloc(1, sizeof(*af));
if (af == NULL)
log_err(1, "calloc");
af->af_mount_time = time(NULL);
af->af_fsid = fsid;
strlcpy(af->af_mountpoint, mountpoint, sizeof(af->af_mountpoint));
TAILQ_INSERT_TAIL(&automounted, af, af_next);
return (af);
}
static void
automounted_remove(struct automounted_fs *af)
{
TAILQ_REMOVE(&automounted, af, af_next);
free(af);
}
static void
refresh_automounted(void)
{
struct automounted_fs *af, *tmpaf;
struct statfs *mntbuf;
int i, nitems;
nitems = getmntinfo(&mntbuf, MNT_WAIT);
if (nitems <= 0)
log_err(1, "getmntinfo");
log_debugx("refreshing list of automounted filesystems");
TAILQ_FOREACH(af, &automounted, af_next)
af->af_mark = false;
for (i = 0; i < nitems; i++) {
if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
log_debugx("skipping %s, filesystem type is autofs",
mntbuf[i].f_mntonname);
continue;
}
if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
log_debugx("skipping %s, not automounted",
mntbuf[i].f_mntonname);
continue;
}
af = automounted_find(mntbuf[i].f_fsid);
if (af == NULL) {
log_debugx("new automounted filesystem found on %s "
"(FSID:%d:%d)", mntbuf[i].f_mntonname,
mntbuf[i].f_fsid.val[0], mntbuf[i].f_fsid.val[1]);
af = automounted_add(mntbuf[i].f_fsid,
mntbuf[i].f_mntonname);
} else {
log_debugx("already known automounted filesystem "
"found on %s (FSID:%d:%d)", mntbuf[i].f_mntonname,
mntbuf[i].f_fsid.val[0], mntbuf[i].f_fsid.val[1]);
}
af->af_mark = true;
}
TAILQ_FOREACH_SAFE(af, &automounted, af_next, tmpaf) {
if (af->af_mark)
continue;
log_debugx("lost filesystem mounted on %s (FSID:%d:%d)",
af->af_mountpoint, af->af_fsid.val[0], af->af_fsid.val[1]);
automounted_remove(af);
}
}
static int
unmount_by_fsid(const fsid_t fsid, const char *mountpoint)
{
char *fsid_str;
int error, ret;
ret = asprintf(&fsid_str, "FSID:%d:%d", fsid.val[0], fsid.val[1]);
if (ret < 0)
log_err(1, "asprintf");
error = unmount(fsid_str, MNT_NONBUSY | MNT_BYFSID);
if (error != 0) {
if (errno == EBUSY) {
log_debugx("cannot unmount %s (%s): %s",
mountpoint, fsid_str, strerror(errno));
} else {
log_warn("cannot unmount %s (%s)",
mountpoint, fsid_str);
}
} else
rpc_umntall();
free(fsid_str);
return (error);
}
static time_t
expire_automounted(time_t expiration_time)
{
struct automounted_fs *af, *tmpaf;
time_t now;
time_t mounted_for, mounted_max = -1;
int error;
now = time(NULL);
log_debugx("expiring automounted filesystems");
TAILQ_FOREACH_SAFE(af, &automounted, af_next, tmpaf) {
mounted_for = difftime(now, af->af_mount_time);
if (mounted_for < expiration_time) {
log_debugx("skipping %s (FSID:%d:%d), mounted "
"for %jd seconds", af->af_mountpoint,
af->af_fsid.val[0], af->af_fsid.val[1],
(intmax_t)mounted_for);
if (mounted_for > mounted_max)
mounted_max = mounted_for;
continue;
}
log_debugx("filesystem mounted on %s (FSID:%d:%d), "
"was mounted for %ld seconds; unmounting",
af->af_mountpoint, af->af_fsid.val[0], af->af_fsid.val[1],
(long)mounted_for);
error = unmount_by_fsid(af->af_fsid, af->af_mountpoint);
if (error != 0) {
if (mounted_for > mounted_max)
mounted_max = mounted_for;
}
}
return (mounted_max);
}
static void
usage_autounmountd(void)
{
fprintf(stderr, "usage: autounmountd [-r time][-t time][-dv]\n");
exit(1);
}
static void
do_wait(int kq, time_t sleep_time)
{
struct timespec timeout;
struct kevent unused;
int nevents;
if (sleep_time != -1) {
assert(sleep_time > 0);
timeout.tv_sec = sleep_time;
timeout.tv_nsec = 0;
log_debugx("waiting for filesystem event for %ld seconds",
(long)sleep_time);
nevents = kevent(kq, NULL, 0, &unused, 1, &timeout);
} else {
log_debugx("waiting for filesystem event");
nevents = kevent(kq, NULL, 0, &unused, 1, NULL);
}
if (nevents < 0) {
if (errno == EINTR)
return;
log_err(1, "kevent");
}
if (nevents == 0) {
log_debugx("timeout reached");
assert(sleep_time > 0);
} else {
log_debugx("got filesystem event");
}
}
int
main_autounmountd(int argc, char **argv)
{
struct kevent event;
struct pidfh *pidfh;
pid_t otherpid;
const char *pidfile_path = AUTOUNMOUNTD_PIDFILE;
int ch, debug = 0, error, kq;
time_t expiration_time = 600, retry_time = 600, mounted_max, sleep_time;
bool dont_daemonize = false;
while ((ch = getopt(argc, argv, "dr:t:v")) != -1) {
switch (ch) {
case 'd':
dont_daemonize = true;
debug++;
break;
case 'r':
retry_time = atoi(optarg);
break;
case 't':
expiration_time = atoi(optarg);
break;
case 'v':
debug++;
break;
case '?':
default:
usage_autounmountd();
}
}
argc -= optind;
if (argc != 0)
usage_autounmountd();
if (retry_time <= 0)
log_errx(1, "retry time must be greater than zero");
if (expiration_time <= 0)
log_errx(1, "expiration time must be greater than zero");
log_init(debug);
pidfh = pidfile_open(pidfile_path, 0600, &otherpid);
if (pidfh == NULL) {
if (errno == EEXIST) {
log_errx(1, "daemon already running, pid: %jd.",
(intmax_t)otherpid);
}
log_err(1, "cannot open or create pidfile \"%s\"",
pidfile_path);
}
if (dont_daemonize == false) {
if (daemon(0, 0) == -1) {
log_warn("cannot daemonize");
pidfile_remove(pidfh);
exit(1);
}
}
pidfile_write(pidfh);
TAILQ_INIT(&automounted);
kq = kqueue();
if (kq < 0)
log_err(1, "kqueue");
EV_SET(&event, 0, EVFILT_FS, EV_ADD | EV_CLEAR, VQ_MOUNT | VQ_UNMOUNT, 0, NULL);
error = kevent(kq, &event, 1, NULL, 0, NULL);
if (error < 0)
log_err(1, "kevent");
for (;;) {
refresh_automounted();
mounted_max = expire_automounted(expiration_time);
if (mounted_max == -1) {
sleep_time = mounted_max;
log_debugx("no filesystems to expire");
} else if (mounted_max < expiration_time) {
sleep_time = difftime(expiration_time, mounted_max);
log_debugx("some filesystems expire in %ld seconds",
(long)sleep_time);
} else {
sleep_time = retry_time;
log_debugx("some expired filesystems remain mounted, "
"will retry in %ld seconds", (long)sleep_time);
}
do_wait(kq, sleep_time);
}
return (0);
}
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